What is Erlang?

The Erlang website tells us:

Erlang is a programming language used to build massively scalable soft real-time systems with requirements on high availability. Some of its uses are in telecoms, banking, e-commerce, computer telephony, and instant messaging. Erlang’s runtime system has built-in support for concurrency, distribution, and fault tolerance.

Erlang uses concurrent processes to structure the application. These processes do not share memory and communicate asynchronously by passing messages. Erlang processes are very lightweight and belong to the language itself, not to the operating system. That is why it is very present in telecommunications applications or even in social networks such as Twitter.

Install Erlang on Ubuntu 20.04

Erlang is not present in the Ubuntu 20.04 repositories although it is very easy to install. To do this, open a terminal from the main menu and make sure the operating system is fully updated.

sudo apt update
sudo apt upgrade

With this step, the system will be up to date.

As Erlang is not present in the official Ubuntu repositories it is necessary to resort to other methods. Fortunately, the Erlang development team provides us with a repository that we have to add to perform the installation.

So, first, download and add the GPG key from it.

wget -O- https://packages.erlang-solutions.com/ubuntu/erlang_solutions.asc | sudo apt-key add -
--2021-04-08 17:11:49--  https://packages.erlang-solutions.com/ubuntu/erlang_solutions.asc
Resolving packages.erlang-solutions.com (packages.erlang-solutions.com)... 13.226.159.11, 13.226.159.86, 13.226.159.60, ...
Connecting to packages.erlang-solutions.com (packages.erlang-solutions.com)|13.226.159.11|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 3133 (3.1K) [text/plain]
Saving to: ‘STDOUT’

-                                          100%[=====================================================================================>]   3.06K  --.-KB/s    in 0s      

2021-04-08 17:11:50 (453 MB/s) - written to stdout [3133/3133]

OK

Now you can add the repository to the system with the following command

echo "deb https://packages.erlang-solutions.com/ubuntu focal contrib" | sudo tee /etc/apt/sources.list.d/erlang.list

To apply this change, you have to refresh APT

sudo apt update

And finally, you can install Erlang

sudo apt install erlang
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:
  adwaita-icon-theme erlang-appmon erlang-asn1 erlang-base erlang-common-test erlang-crypto erlang-debugger erlang-dev erlang-dialyzer erlang-diameter erlang-edoc
  erlang-eldap erlang-erl-docgen erlang-et erlang-eunit erlang-ftp erlang-gs erlang-ic erlang-inets erlang-inviso erlang-megaco erlang-mnesia erlang-observer
  erlang-odbc erlang-os-mon erlang-parsetools erlang-percept erlang-pman erlang-public-key erlang-reltool erlang-runtime-tools erlang-snmp erlang-ssh erlang-ssl
  erlang-syntax-tools erlang-test-server erlang-tftp erlang-toolbar erlang-tools erlang-tv erlang-typer erlang-wx erlang-xmerl fontconfig fontconfig-config
  fonts-dejavu-core gtk-update-icon-cache hicolor-icon-theme humanity-icon-theme libatk-bridge2.0-0 libatk1.0-0 libatk1.0-data libatspi2.0-0 libavahi-client3
  libavahi-common-data libavahi-common3 libcairo-gobject2 libcairo2 libcolord2 libcups2 libdatrie1 libdrm-amdgpu1 libdrm-intel1 libdrm-nouveau2 libdrm-radeon1
  libepoxy0 libfontconfig1 libgdk-pixbuf2.0-0 libgdk-pixbuf2.0-common libgl1 libgl1-mesa-dri libglapi-mesa libglu1-mesa libglvnd0 libglx-mesa0 libglx0 libgraphite2-3
  libgtk-3-0 libgtk-3-common libharfbuzz0b libice6 libjbig0 libjpeg-turbo8 libjpeg8 libjson-glib-1.0-0 libjson-glib-1.0-common liblcms2-2 libllvm11 libnotify4 libodbc1
  libpango-1.0-0 libpangocairo-1.0-0 libpangoft2-1.0-0 libpciaccess0 libpixman-1-0 librest-0.7-0 librsvg2-2 librsvg2-common libsensors-config libsensors5 libsm6
  libsoup-gnome2.4-1 libtcl8.6 libthai-data libthai0 libtiff5 libtk8.6 libvulkan1 libwayland-client0 libwayland-cursor0 libwayland-egl1 libwebp6 libwxbase3.0-0v5
  libwxgtk3.0-gtk3-0v5 libx11-6 libx11-data libx11-xcb1 libxau6 libxcb-dri2-0 libxcb-dri3-0 libxcb-glx0 libxcb-present0 libxcb-render0 libxcb-shm0 libxcb-sync1
  libxcb-xfixes0 libxcb1 libxcomposite1 libxcursor1 libxdamage1 libxdmcp6 libxext6 libxfixes3 libxft2 libxi6 libxinerama1 libxkbcommon0 libxrandr2 libxrender1
  libxshmfence1 libxss1 libxxf86vm1 tcl tcl8.6 tk tk8.6 ubuntu-mono x11-common
Suggested packages:
  erlang-manpages erlang-doc xsltproc fop erlang-ic-java colord cups-common gvfs liblcms2-utils libmyodbc odbc-postgresql tdsodbc unixodbc-bin librsvg2-bin lm-sensors
  tcl-tclreadline
.
.
.

To check that everything has been successful, you can log in to the Erlang shell.

erl
Erlang/OTP 23 [erts-11.1.7] [source] [64-bit] [smp:1:1] [ds:1:1:10] [async-threads:1]

Eshell V11.1.7  (abort with ^G)
1> 

To exit the shell you can press the keys CTRL + C.

Creating a Hello World file to test Erlang

All of the above is meaningless if we don’t run a Hello World file which is the ultimate test of Erlang’s performance.

With a text editor, create a file called helloworld.erl.

nano helloworld.erl

And add the following

-module(helloworld).
	-export([hello_world/0]).

	hello_world() -> io:fwrite("hello, world from osradar.com\n").

Don’t forget to put . at the end of each line as I have copied it.

Save the changes and close the editor.

Now access the Erl shell again.

erl

And compile the file:

c(helloworld).

Then, run the function in the file.

helloworld:hello_world().

And with this, Erlang will be ready.

Conclusion

Erlang is an important language that for many people goes unnoticed but it is still very useful to dedicate some time to it. Installing it in a system as popular as Ubuntu is something quite simple and within everyone’s reach.

The post How to install Erlang on Ubuntu 20.04? appeared first on Linux Windows and android Tutorials.

The File Transfer Protocol is a protocol that allows two remote computers to share files over a network. Usually, this happens from a server computer to a client computer. Usually, this happens through ports 20 and 21

Companies that have an intranet for daily work, usually have an FTP server configured to make files available to everyone and in Ubuntu 20.04 it is easy to do so.

Creating an FTP server on Ubuntu 20.04

Several daemons allow you to create the FTP server, however, I consider the easiest and fastest to VSFTPD. Besides all this, it works without problems and without making too many strange configurations.

So, open a terminal and update the system.

:~$ sudo apt update
:~$ sudo apt upgrade

And now, install the VSFTPD daemon.

:~$ sudo apt install vsftpd
Reading package lists… Done
Building dependency tree
Reading state information… Done
The following additional packages will be installed:
ssl-cert
Suggested packages:
openssl-blacklist
The following NEW packages will be installed:
ssl-cert vsftpd
0 upgraded, 2 newly installed, 0 to remove and 0 not upgraded.
Need to get 132 kB of archives.
After this operation, 402 kB of additional disk space will be used.
Do you want to continue? [Y/n

Like all services in Debian, it will start by default. To see if it is running correctly, use systemctl.

:~$ sudo systemctl status vsftpd
● vsftpd.service - vsftpd FTP server
Loaded: loaded (/lib/systemd/system/vsftpd.service; enabled; vendor preset: enabled)
Active: active (running) since Sun 2020-05-17 02:34:40 UTC; 1min 17s ago
Main PID: 1337 (vsftpd)
Tasks: 1 (limit: 506)
Memory: 844.0K
CGroup: /system.slice/vsftpd.service
└─1337 /usr/sbin/vsftpd /etc/vsftpd.conf
May 17 02:34:40 osradar systemd[1]: Starting vsftpd FTP server…
May 17 02:34:40 osradar systemd[1]: Started vsftpd FTP server.

The demon already has a default configuration, but we have to modify it to our liking.

Let’s go for it.

Configuring the FTP server

All the VSFTPD configuration is in the /etc/vsftpd.conf file, so before modifying it is convenient to make a backup of it. In case something goes wrong, we can go back to the original and reverse any wrong we have done.

:~$ sudo cp /etc/vsftpd.conf /etc/vsftpd.conf.bak

If you display the contents of the file, you will see that it is very extensive. But that’s because it’s so well documented, it’s quite easy to understand.

Let’s start by having the server actively listen.

listen=YES

If you are not going to use IPv6 then you should disable the support:

listen_ipv6=NO

It is also not advisable to allow access to anonymous. Although sometimes it can be useful.

anonymous_enable=NO

By default, on an FTP server, a client can only download files and not upload them. However, it is a good idea to leave it active.

local_enable=YES
write_enable=YES

By default, FTP works by 20.

connect_from_port_20=YES

Although you can change it with this directive:

listen_port=XX

You can use the key combination CTRL + W to go directly to the line you are looking for.

When you are ready, save your changes with CTRL + O and close the file with CTRL + X.

Omitting the comments in the file should look like this:

listen=YES
listen_ipv6=NO
anonymous_enable=NO
local_enable=YES
write_enable=YES
local_umask=022
dirmessage_enable=YES
use_localtime=YES
xferlog_enable=YES
connect_from_port_20=YES
secure_chroot_dir=/var/run/vsftpd/empty
pam_service_name=vsftpd
rsa_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
rsa_private_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
ssl_enable=NO

To display the file without the comments, run the following command:

:~$ sudo cat /etc/vsftpd.conf | grep -v "^#"

Creating a new FTP user

Now there is a new user for the FTP server. This user can be created from the same terminal.

:~$ sudo useradd -m user1

And then, assign him a password:

:~$ sudo passwd user1

So,now we can test the new FTP server on Ubuntu 20.04.

Testing the FTP server on Ubuntu 20.04

Now the moment of truth has arrived. Let’s try the FTP server.

One way is to open a terminal and try to access it with the ftp command and the server’s IP address.

:~$ ftp 192.168.250.20
Connected to 192.168.250.20.
220 (vsFTPd 3.0.3)
Name (192.168.250.20:angelo): user1
331 Please specify the password.
Password:
230 Login successful.
Remote system type is UNIX.
Using binary mode to transfer files.
ftp>

Once the connection to the server is established, you will be asked for the username and password.

If the login is correct you will already have access to download and upload files.

Another way is from the web browser of your preference to access the FTP server. In my case, I access the following address ftp://192.168.250.20 and it is required immediately to log in.

By writing correctly the credentials created, I can access the folder that this user has dedicated.

To take better advantage of FTP, it is convenient to install a tool such as Filezilla.

So, that’s it. The FTP server is alive.

Conclusion

An FTP server can be a great way to share files on a network. Especially if it’s for an organization or on an intranet. You saw that setting one up in Ubuntu 20.04 is a pretty simple thing.

Please share this post, join our Telegram channel and if you want buy us a coffee.

The post How to set up an FTP server on Ubuntu 20.04? appeared first on Linux Windows and android Tutorials.

PHPMyAdmin is an open-source application created in PHP that provides the administration of a MySQL or MariaDB database from a comfortable web interface. It is simply installed on the server, we make a few small configurations and that’s it. That’s it. Without consuming many resources you will have a quality application.

So, let’s get started.

Install PHPMyAdmin on Ubuntu 20.04

1.- Install LAMP on Ubuntu 20.04

PHPMyAdmin is created in PHP, so we are talking about a web application. Therefore, it requires a correctly installed LAMP server.

How to install LAMP on Ubuntu 20.04?

Once the installation is finished, you can continue.

I also advise you to create a dedicated user for PHPMyAdmin.

2.- Installing PHPMyAdmin on Ubuntu 20.04

For now, the last official version of PHPMyAdmin is 5.0.2, so we will proceed to download it using wget.

:~$ cd /tmp/
:~$ wget https://files.phpmyadmin.net/phpMyAdmin/5.0.2/phpMyAdmin-5.0.2-all-languages.zip

Then, decompress it into another folder dedicated to PHPMyAdmin as /usr/share

:~$ sudo unzip phpMyAdmin-5.0.2-all-languages.zip -d /usr/share/

It is advisable to change the name of the folder to one more easily manipulated like this:

:~$ sudo mv /usr/share/phpMyAdmin-5.0.2-all-languages/ /usr/share/phpmyadmin

Also, create the directories that the application will use.

:~$ sudo mkdir -p /var/lib/phpmyadmin/tmp
:~$ sudo mkdir /etc/phpmyadmin/

Then, assign Apache as the owner of the PHPMyAdmin temporary folder.

:~$ sudo chown -R www-data:www-data /var/lib/phpmyadmin

The next step is to copy the default configuration and transform it into the program’s loaded configuration.

:~$ sudo cp /usr/share/phpmyadmin/config.sample.inc.php /usr/share/phpmyadmin/config.inc.php

Then, you have to set a secret blowfish in the PHPMyAdmin configuration file:

:~$ sudo nano /usr/share/phpmyadmin/config.inc.php

In this case I have established the following:

$cfg['blowfish_secret'] = '0sr@dar';

In that same file, set the directory of temporary files that we have created for PHPMyAdmin:

$cfg['TempDir'] = '/var/lib/phpmyadmin/tmp';

Then, save the changes and close the file

Finally, create a new Virtualhost for the application:

:~$ sudo nano /etc/apache2/conf-enabled/phpmyadmin.conf

And add all this content inside:

Alias /phpmyadmin /usr/share/phpmyadmin
     <Directory /usr/share/phpmyadmin>
           Options SymLinksIfOwnerMatch
           DirectoryIndex index.php
     <IfModule mod_php5.c> 
           <IfModule mod_mime.c>
                AddType application/x-httpd-php .php 
           </IfModule>
     <FilesMatch ".+\.php$">
           SetHandler application/x-httpd-php 
     </FilesMatch>
     php_value include_path .
     php_admin_value upload_tmp_dir /var/lib/phpmyadmin/tmp
     php_admin_value open_basedir /usr/share/phpmyadmin/:/etc/phpmyadmin/:/var/lib/phpmyadmin/:/usr/share/php/php-gettext/:/usr/share/php/php-php-gettext/:/usr/share/javascript/:/usr/share/php/tcpdf/:/usr/share/doc/phpmyadmin/:/usr/share/php/phpseclib/
     php_admin_value mbstring.func_overload 0
     </IfModule>
     <IfModule mod_php.c>
          <IfModule mod_mime.c>
              AddType application/x-httpd-php .php
     </IfModule>
          <FilesMatch ".+\.php$">
             SetHandler application/x-httpd-php
          </FilesMatch>
    php_value include_path .
    php_admin_value upload_tmp_dir /var/lib/phpmyadmin/tmp
    php_admin_value open_basedir /usr/share/phpmyadmin/:/etc/phpmyadmin/:/var/lib/phpmyadmin/:/usr/share/php/php-gettext/:/usr/share/php/php-php-gettext/:/usr/share/javascript/:/usr/share/php/tcpdf/:/usr/share/doc/phpmyadmin/:/usr/share/php/phpseclib/
    php_admin_value mbstring.func_overload 0
     </IfModule>
</Directory>

#Authorize for setup 
<Directory /usr/share/phpmyadmin/setup>
      <IfModule mod_authz_core.c>
           <IfModule mod_authn_file.c>
               AuthType Basic
               AuthName "phpMyAdmin Setup"
               AuthUserFile /etc/phpmyadmin/htpasswd.setup
           </IfModule>
      Require valid-user
      </IfModule>
</Directory>

#Disallow web access to directories that don't need it

<Directory /usr/share/phpmyadmin/templates>
     Require all denied
</Directory>

<Directory /usr/share/phpmyadmin/libraries>
     Require all denied
</Directory>

<Directory /usr/share/phpmyadmin/setup/lib>
     Require all denied
</Directory>

Save the changes and close the file.

To apply this new Virtuahost, just restart Apache.

:~$ sudo systemctl restart apache2

Now open your favorite web browser and go to http://your-server/phpmyadmin and you will see the login screen.

Log in and then you can start working.

Conclusion

PHPMyAdmin is a vital tool for many developers. It allows you to visualize MySQL or MariaDB data quickly through a well-designed graphical interface that does not consume many computer resources. Thanks to this post, you can enjoy the latest stable version of PHPMyAdmin on Ubuntu 20.04

Please share this post and join our Telegram channel.

The post Install PHPMyAdmin on Ubuntu 20.04 appeared first on Linux Windows and android Tutorials.